Why do people even want a new Pokemon Stadium game? Let's look at all of the major features of the original and see if they're in Gen 7 already.

>3D Pokemon battles
Standard in Gen 7
>easier Pokemon box management
Standard in Gen 7
>storing Pokemon in the game itself
Pokemon Bank exists
>get cool gift Pokemon
Online events, serial codes, etc. Even Pokemon Bank hands out gift Pokemon sometimes
>provides a challenge for experienced players bored with the normal game
Battle Tree and battling online
>play your games on the big screen and speed them up
This is the only thing that's actually missing from the franchise, but other than the speed up function, since the games are on bigger screens than the Game Boy anyway, it's not much of an issue
>bare bones minigames
Just play any number of spinoff titles

So remind me again why it would be good to have a Pokemon Stadium 3? Oh, right, it's just nostalgiafags that want another entry in a series they liked when they were a kid.